1. Field of the Invention
The present invention relates to oil burners and particularly to those in which liquid fuel oil is heated to the vaporizing point before being introduced to a combustion chamber.
2. Description of the Prior Art
Heating efficiency from oil burners is reduced in efficiency due to three main causes. The first is poor atomization of the oil resulting in incomplete burning. The second, related to the first, is soot built up on heat exchangers, due to imcomplete burning, reducing heat exchanger efficiency and allowing large amounts of heat to pass out the flue. The third is addition of large amount of inert gases such as nitrogen through the air intake resulting in inert gaseous materials absorbing heat and carrying it up the flue. Most gun type atomizing oil burners leave a substantial residue of unburned hydrocarbons as evidenced by orange colored flame and smoke. Burners that come closer to the optimum blue flame are usually overaerated, resulting in losses from inert gases.
A number of burners have been designed with or without a pressure oil atomizing nozzle which heat the oil to its vaporizing point prior to combustion. Examples are found in U.S. Pat. Nos. 1,949,382; 1,968,360; 2,069,960; 2,458,630; 2,675,866 and 2,964,101.
In oil burners of this type, liquid fuel oil may be fed in at a relatively slow velocity onto a heated surface where it is vaporized. This is described for example in U.S. Pat. No. 2,964,101. Separation between the vaporization area and the combustion area has been provided in assorted ways along with varying complexity of means for introducing combustion air. Apparatus such as described in U.S. Pat. Nos. 1,968,360; 2,069,960 and 1,949,382 are believed to be oversimplified and probably inefficient in performance due to inadequate mixing of vaporized fuel and air in the combustion zone. The apparatus described in the other patents appear to be complex and expensive and costly in manufacture.